1. Field of the Invention
The present invention may relate to a plant for filling containers and a method of operating a plant for filling containers.
2. Background Information
In a known method of cleaning filter equipment, the filter cake produced at the filter on the side of the unfiltrate of the filter equipment is removed thereby that the interior space at the inlet-side, as well as part of the filtrate space positioned above the interior space at the inlet-side, is filled with water from the unfiltrate side when the exit-side is closed, such that the air positioned above the water is compressed in the filtrate space. Upon introduction of water and compression of the air in the upper space of the filtrate space, a discharge is opened all of a sudden such that the air under pressure causes an intense back-flow of the water present in the filtrate space, through the filter, and thereby the filter cake accumulated on the unfiltrate side of the filter is removed from the filter, and is mixed with the water present in the unfiltrate space, and with this is removed through the drain from the filter equipment.
This method is rather simple, but has the decisive disadvantage which is to be seen therein that the filter cake removed from the filter is mixed with such a volume of water which is nearly equal to the total volume of both interior spaces of the filter equipment. Since this water which includes the filter cake can not be passed to sewage in this condition, subsequently a laborious separation of the sludge from the water is necessary. This is the cause of high equipment costs and not insignificant operating costs. Subsequently, the unfiltrate space or, respectively, its walls need to be cleaned.
In a further known method for cleaning filter equipment with installed filter, a cleaning fluid is brought to an overpressure, in a separate container, and for carrying out the cleaning, is brought, via an inlet conduit, to the removal-side of the filter equipment, and from there is pressed through the filter in the direction opposite to the direction of filtration. For moving the cleaning fluid from the accumulated, or special, container to the filter equipment, a gaseous medium under overpressure is used.
As cleaning medium, usefully, water is employed and as gaseous medium air is used. For distribution of the cleaning fluid serve nozzle-shaped constrictions arranged, respectively, at the candle end on the removal-side, or impact bodies arranged at a distance from such constriction in the candle interior, by which the in-flowing cleaning fluid is deflected to all sides in the direction of the interior walls of the candles.
This has the disadvantage that the nozzle-shaped constrictions are present for the introduction of cleaning fluid into the interior of the filter candle, as well as for the air under pressure, such that on termination of a pressure impulse, a post-flow, or, in other words, a trailing or tailing type of flow behavior, of cleaning fluid is not possible. Cleaning of the interior of the boiler or, respectively, its walls is not possible with this method.
Furthermore, it is known to clean the lower portion of a boiler filter with a group of nozzles which extend vertically and in circumferential manner.
Such a cleaning method allows only cleaning of the free space beneath the filter candles. Wall sections disposed above the free space of the boiler filter, accordingly, can not be impacted and cleaned in accordance with the requirements. In addition, due to being fixedly secured at a rotor, the nozzle groups create a uniform or, particularly, a stream of spray which is constant with respect to position, which allows only impacting of definite areas.
In other words, one possible advantage of the present invention, in at least one possible embodiment, is concerned in one aspect with cleaning of the filter housing of filters with candles or elements of a tubular filter arrangement, in which vertical tubes or cartridges, in other words, candles, are supported by a filtrate-chamber tube sheet in a vertical cylindrical vessel, compare pages 18-92 and 18-93 in xe2x80x9cLiquid-Solid Operations and Equipmentxe2x80x9d in PERRY""S CHEMICAL ENGINEERS"" HANDBOOK, Seventh Edition, Robert H. Perry and Don W. Green, 1997, The McGraw-Hill Companies, Inc., ISBN 0-07-049841-5, incorporated herein by reference.
Also in other words, in filtration is achieved the separation of two phases, particulate form, i.e., solid particles or liquid droplets in suspension, and continuous, i.e., liquid or gas, from a mixture, herein also referred to as unfiltrate or liquid to be filtered, by passing the mixture through a porous medium. This may be cylindrical element filters, often referred to as candle filters, in which cylindrical elements or sleeves may be mounted vertically and suspended from a header sheet, which divides the filter vessel into two separate compartments. One possible advantage of candle filters or filter elements may be that as the cake grows on the tubular elements the filtration area increases and the thickness of a given volume of cake is therefore less than it would be on a flat element, compare Filtration, in Volume 10 of KIRK-OTHMER, ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, Fourth Edition, Jacqueline I. Kroschwitz, editor, 1993, John Wiley and Sons, Inc., ISBN 0-471-52679-9 (v. 10), also incorporated herein by reference.
One possible object of the present invention may be to contact the inner walls of such a filter commencing already at the upper portion, essentially in all-around manner with cleaning liquid.
In at least one possible embodiment, the present invention preferably teaches that this object can be accomplished by the method of cleaning filter housings of the type described in the foregoing, thereby that in the upper region of the unfiltrate portion a cleaning medium is directed against the lower wall of the intermediate bottom and/or the upper region of the wall of the unfiltrate portion, with such a direction of flow that a substantially closed cleaning film, flow, or sheet of water or other liquid can be guided, from the upper wall of the unfiltrate portion, downwardly along this wall.
In at least one possible embodiment of the present invention, it may be further suggested that the cleaning medium is introduced in the upper region of the unfiltrate portion from the exterior and is, as a film, guided in circumscribing manner.
For a boiler filter it may be further contemplated that the cleaning device is configured as one in the upper, outer region of the unfiltrate portion extending spray ring, the spray nozzles of which are directed against the lower boiler wall of the intermediate bottom and/or are directed against the upper region of the wall of the unfiltrate portion and co-act with a flow directing apparatus.
Furthermore, it may be contemplated that the cleaning device is comprised of a recess in the support region of the intermediate bottom upon the unfiltrate portion, and this can be contacted with cleaning liquid introduced from the exterior.
With the method in accordance with at least one possible embodiment of the present invention and a proposed apparatus, an essentially advantageous cleaning of the wall parts of such an unfiltrate portion may be carried out in an essentially simple manner. Particularly, there may be provided a substantially closed rinsing film or sheet which, practically, may take its course from the upper wall region to the bottom and flushes away the still softened components of the unfiltrate or, particularly, the sludge, cake, filter cake, or deposit mass.
When use is made of a circumferential flush pipe, inlet pipe, or spray ring, or a plurality of at least one of these structures, by aimed distribution of the cleaning liquid with flow direction against the upper wall parts, which are sloped accordingly, there may be produced an optimal film. This formation can experience a further enhancement, through periodical impacting of the nozzles of such a spray ring. Particularly, an additional peeling effect may be attained.
The same effect may also be achieved, when the cleaning liquid is introduced from the exterior and its volume is controlled in such a manner that also a rinsing film is passed to the walls.
In accordance with one aspect of the present invention, there may be provided a method of operating and cleaning filter apparatus having filter candles, at least a portion for receiving liquid to be filtered, and a portion for receiving liquid when filtered, said method comprising the steps of: (a) moving a first batch of liquid to be filtered in a first direction from said portion for receiving liquid to be filtered through said filter candles from a first surface to a second surface of said filter candles and thereby collecting solids at said first surface of said filter candles as filter cake; (b) terminating filtering according to step (a); (c) initiating a first flow of cleaning liquid along a first flow path, over said second surface, for inducing removal of filter cake from said filter candles by flowing a sheet of cleaning liquid over said second surface; (d) pressurizing and directing a flow of gaseous medium in a second flow path separate from said first flow path to force said sheet of cleaning liquid flowing on said second surface through said filter candles from said second surface to said first surface, to dislodge filter cake on said first surface; (e) removing filter cake from said first surface of said filter candles by the interaction of cleaning liquid and gaseous medium; (f) initiating a second flow of cleaning liquid to supply at least said portion for receiving liquid to be filtered with cleaning liquid; (g) directing said second flow of cleaning liquid along the wall of said portion for receiving liquid to be filtered thereby to dislodge solids from said wall; (h) terminating cleaning according to step (e); (i) terminating said second flow of cleaning liquid; (j) removing dislodged solids; and (k) moving a second batch of suspension in said first direction through said filter elements.
In accordance with another aspect of our invention, there may be provided a method of operating and cleaning filter apparatus having filter candles, at least a portion for receiving a liquid to be filtered, and a portion for receiving liquid when filtered, said method comprising the steps of: (a) moving a first batch of liquid to be filtered in a first direction from said portion for receiving a liquid to be filtered through said filter candles from a first surface to a second surface of said filter candles and thereby collecting solids at said first surface of said filter candles as filter cake; (b) terminating filtering according to step (a); (c) initiating a first flow of cleaning liquid along a first flow path, over said second surface, for inducing removal of filter cake from said filter candles by flowing a sheet of cleaning liquid over said second surface; (d) pressurizing and directing a flow of gaseous medium in a second flow path separate from said first flow path to force said sheet of cleaning liquid flowing on said second surface through said filter candles from said second surface to said first surface, to dislodge filter cake on said first surface; (e) removing filter cake from said filter candles by the interaction of cleaning liquid and gaseous medium; (f) initiating a second flow of cleaning liquid to supply at least said portion for receiving liquid to be filtered with cleaning liquid; (g) directing said second flow of cleaning liquid to dislodge solids; (h) terminating cleaning according to Step (e); (i) terminating said second flow of cleaning liquid; (j) removing dislodged solids; and (k) moving a second batch of suspension in said first direction through said filter elements.
In accordance with yet another aspect of our invention, there may be provided a method of operating and cleaning filter apparatus having filter candles, at least a portion for receiving liquid to be filtered, and a portion for receiving liquid when filtered, said method comprising the steps of: (a) moving a first batch of liquid to be filtered in a first direction from said portion for receiving a liquid to be filtered through said filter candles from a first surface to a second surface of said filter candles and thereby collecting solids at said first surface of said filter candles as filter cake; (b) terminating filtering according to step (a); (c) initiating a first flow of cleaning liquid to said second surface; (d) pressurizing and directing a flow of gaseous medium to force cleaning liquid through said filter candles from said second surface to said first surface, to dislodge filter cake on said first surface; (e) removing filter cake from said filter candles by the interaction of cleaning liquid and gaseous medium; (f) initiating a second flow of cleaning liquid to supply at least said portion for receiving liquid to be filtered with cleaning liquid; (g) directing said second flow of cleaning liquid on the wall of said portion for receiving liquid to be filtered in a flowing sheet of cleaning liquid thereby to dislodge solids from said wall; (h) terminating said first flow of cleaning liquid according to step (c); (i) terminating flow of gaseous medium according to step (d);(j) terminating said second flow of cleaning liquid according to step (f); (k) removing dislodged solids; and (1) moving a second batch of suspension in said first direction through said filter elements.
Still in accordance with another aspect of our invention, there may be provided a method of operating and cleaning filter apparatus having filter candles, at least a portion for receiving a liquid to be filtered, and a portion for receiving liquid when filtered, said method comprising the steps of: (a) moving a first batch of liquid having solids suspended therein in a first direction from said portion for receiving liquid to be filtered through said filter candles from a first surface to a second surface of said filter candles and thereby collecting solids at said first surface of said filter candles as filter cake; (b) terminating filtering according to step (a); (c) removing filter cake from said filter candles by the interaction of cleaning liquid and gaseous medium; (d) initiating a second flow of cleaning liquid to supply at least said portion for receiving liquid to be filtered with cleaning liquid; (e) directing said second flow of cleaning liquid on the wall of said portion for receiving liquid to be filtered in a flowing sheet of cleaning liquid thereby to dislodge solids from said wall; (f) terminating cleaning according to step (c); (g) terminating said second flow of cleaning liquid; (h) removing dislodged solids; and (i) moving a second batch of suspension in said first direction through said filter elements.
A further aspect of our invention may reside broadly in a plant in which containers are filled with liquid, comprising: apparatus for moving containers to a filling machine; a machine for filling said containers with liquid when filtered; apparatus for removing filled containers from said filling machine, said liquid when filtered being provided by apparatus for providing a liquid to be filtered in a first batch to a candle filter apparatus comprising: a portion for receiving liquid to be filtered; a portion for receiving liquid when filtered; an intermediate bottom between said portion for receiving liquid to be filtered and said portion receiving liquid when filtered; a plurality of filter candles operatively connected to said intermediate bottom, to filter liquid received from said portion for receiving liquid to be filtered and passing filtered liquid to said portion for receiving liquid when filtered, and said filter candles extending into said portion for receiving liquid to be filtered; apparatus for moving a first batch of liquid to be filtered in a first direction from said portion for receiving liquid to be filtered through said filter candles from a first surface to a second surface of said filter candles and thereby collecting solids at said first surface of said filter candles as filter cake; apparatus for terminating filtering; apparatus for initiating a first flow of cleaning liquid along a first flow path, over said second surface, for inducing removal of filter cake from said filter candles by flowing a sheet of cleaning liquid over said second surface; apparatus for pressurizing and directing a flow of gaseous medium in a second flow path separate from said first flow path to force said sheet of cleaning liquid flowing on said second surface through said filter candles from said second surface to said first surface, to dislodge filter cake on said first surface; apparatus for removing filter cake from said first surface of said filter candles by the interaction of cleaning liquid and gaseous medium; apparatus for initiating a second flow of cleaning liquid to supply at least said portion for receiving liquid to be filtered with cleaning liquid; apparatus for directing said second flow of cleaning liquid along the wall of said portion for receiving liquid to be filtered thereby to dislodge solids from said wall; apparatus for terminating said first flow of cleaning liquid; apparatus for terminating said second flow of cleaning liquid; apparatus for removing dislodged solids; and apparatus for moving a second batch of suspension in said first direction through said filter elements.
In accordance with another aspect of our invention, there may be provided a candle filter apparatus, comprising: a vessel having a portion for receiving liquid to be filtered and a portion for receiving liquid when filtered; a plurality of filter candles operatively connected to said portion for receiving liquid to be filtered, to filter liquid received from said portion for receiving liquid and passing it to said portion for receiving liquid when filtered; and apparatus connected to said vessel and configured to direct cleaning liquid at least against the wall of said portion for receiving liquid to be filtered to dislodge solids from said wall.
The above-discussed embodiments of the present invention will be described further hereinbelow with reference to the accompanying figures. When the word xe2x80x9cinventionxe2x80x9d is used in this specification, the word xe2x80x9cinventionxe2x80x9d includes xe2x80x9cinventionsxe2x80x9d, that is, the plural of xe2x80x9cinventionxe2x80x9d. By stating xe2x80x9cinventionxe2x80x9d, the Applicants do not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintain that this application may include more than one patentably and non-obviously distinct invention. The Applicants hereby assert that the disclosure of this application may include more than one invention, that these inventions may be patentable and non-obvious one with respect to the other.